By Mere Observation
A number is divisible by 11 if the alternating sum of the digits is 0 or a multiple of 11. This also means that the difference between the sum of the odd-placed digits and the sum of the even-placed digits…
A number is divisible by 11 if the alternating sum of the digits is 0 or a multiple of 11. This also means that the difference between the sum of the odd-placed digits and the sum of the even-placed digits…